1. Field of the Invention
The present invention relates to a method and device for generating or producing road and/or street data for a digital map.
2. Description of the Related Art
Digital maps find application, for example, in connection with vehicle navigation systems. Currently this sort of digital map is put together with the aid of pre-existing printed maps. Especially the courses of the roads and streets (i.e. positions of successive points over which the roads and streets extend) are acquired and digitally coded for this purpose. The known methods for digitizing a printed map provide for manually acquiring the courses of the roads and streets using a digitizing tablet. Thus the streets and roads to be digitized must already be mapped. This method is very labor-intensive and expensive however a high quality digital map is the result. Another known method for digitization of map data comprises scanning the map material and vectoring the scanned data by image processing methods. The courses of the streets and roads can be extracted from vectors obtained from the vectoring. This latter method requires little manual work but can lead to quality problems in the resulting digital map due to unmonitored automatic image processing. To reliably update the digital map, independently of the method used for the digitalization of the map material, the courses of the roads and streets must be continually monitored and checked. For example, the work required for producing or updating a digital map is increased because of new street and road construction and other construction, which changes the courses of the roads and streets temporarily or permanently.